Bonding together two plastic mouldings by intermediate layer - by applying e.g. film to one and foam to other moulding and then applying intermediate layer by plasma polymerisation

摘要

Plastic mouldings are bonded together with other plastic components and with a plastic film, foam or another moulding in particular, by applying an intermediate layer to at least one of the faces to be joined, heating, and forming a weld between the two mouldings, using thermoplastics (and polyolefins in particular) for the purpose. The intermediate layer concerned is applied by plasma polymerisation so that it has a lower melting pt. than (at least) the mouldings; the layer chosen is of the same chemical type as the mouldings/films/foams but with a different molecular chain length or cross-linking structure.. The process is suitable for e.g. bonding hard to softer/elastic mouldings used in car interiors (e.g. instrument panels). The figure shows the principle where a moulding (1) requires to be bonded to a foam (2) and a film (3). For this purpose an intermediate layer (4) is placed between moulding and foam (2) and between foam and film (3). The intermediate layer (4) is applied by plasma polymerisation on to the moulding (1) and the film (3) (or simply on just the one surface, where feasible). ADVANTAGE - The method simplifies bonding e.g. polyolefins. It is simpler than using hot melt adhesive films (which cannot be used for complicated shapes). It is suitable for use with thin-walled mouldings.